Test for Oxygen
Oxygen can be distinguished from all other gases except dinitrogen oxide, N2O by its rekindling of a glowing splint of wood.
It is however distinguished from N2O by the following observations:
(1). Oxygen does not have smell, while N2O has a sweet, sickly smell.
(2). Oxygen produces brown fumes of nitrogendioxide, NO2 with nitrogen monoxide,
2NO(g) + O2(g) → 2NO2(g) (brown fumes),
while N2O does not.